Evaluation of the effects of crude glycerol on the production and properties of novel polyhydroxyalkanoate copolymers containing high 11‐hydroxyoctadecanoate by Cupriavidus necator IPT 029 and Bacillus megaterium IPT 429

Abstract

Crude glycerol (CG), a by-product from biodiesel production, is a carbon source with potential as feedstock for polyhydroxyalkanoate (PHA) production. PHAs are biological macromolecules synthesized by microorganisms as intracellular carbon and energy storage granules. PHA production and its properties were investigated using Cupriavidus necator IPT 029 and Bacillus megaterium IPT 429 cultivated with CGs from different origins. The highest PHA extraction percentage (71.56% [w/v]) occurred when C. necator IPT 029 metabolized CG 3 (from the processing of biodiesel from castor bean oil). The gas chromatography-mass spectrometry analyses revealed novel PHA constituents as building blocks of medium (3-hydroxytetradecanoate) and long (11-hydroxyoctadecanoate) chains. Molar mass distribution revealed range of 121-6900 kDa. The initial degradation temperature ranged from 181.83 to 287.50°C and the crystallinity ranged from 35.30 to 66.70%. The results obtained indicate that C. necator IPT 029 from CG 3 could produce copolymers with industrially applicable thermophysical properties. Figure 4. GC-MS chromatograms and mass spectra: PHA produced by C. necator IPT 029 with CG 3 (from the processing of biodiesel from castor bean oil) (I) and PHA produced by B. megaterium IPT 429 with glucose (II).

Challenges of scaling-up PHA production from waste streams. A review

“…All industrial, not agro-alimentary wastes are generated by biodiesel manufacturing: crude glycerol (Gómez-Cardozo et al, 2016;Bera et al, 2015;Ribeiro et al, 2016;Ray et al, 2016;de Paula et al, 2016); oil cake hydrolysate (Bera et al, 2015) and biodiesel fatty acid by-product from glycerol purification (Cruz et al, 2016). In addition, carboxylic acids contained in glycerol anaerobic digestion effluent from 1,3-propanediol production were successfully studied in Pan et al, (2016) as carbon source.…”

“…Concretely, 61% of the revised manuscript in the period 2014-2016 used pure culture at lab-scale (Table 2). Prior to the cultivation and PHA generation, pure strain cultures were usually maintained by the addition of different mixtures of synthetic compounds such as agar, tryptone, yeast extract or other nutrients, in accordance with the strain requirements (Cruz et al, 2015;Ribeiro et al, 2016;Pan et al, 2016). The genus Bacillus was the most employed in pure culture (Patel et al, 2015;Ribeiro et al, 2016;Pan et al, 2016;Rodriguez-Contreras et al, 2016;Venkateswar-Reddy et al, 2015).…”

ASSESSMENT OF POLYHYDROXYALKANOATE SYNTHESIS IN SUBMERGED CULTIVATION OF Cupriavidus necator AND Burkholderia cepacia STRAINS USING SOYBEAN AS SUBSTRATE

“…Nevertheless, the polyesters produced by B. cepacia IPT 119 and 400 displayed thermal performances superior to what was observed in the results reported by Ribeiro et al (2016) and Ray et al (2016) for PHA synthetized by Bacillus megaterium and Pannonibacter phragmitetus, respectively.…”

“…PHA degrees of crystallinity reported in the literature (Campos et al, 2014;Ribeiro et al, 2015;Ribeiro et al, 2016;Bengtsson et al, 2010) are highly dependable on the substrate and on the producer microorganism, with values ranging from 66.7% to 35.3%. Comparatively, the polymers produced in this paper exhibited low crystallinity and great potential for industrial processing and applications based on their molecular arrangement.…”

“…Yet, most studies are focused on the use of substrates predominantly constituted by carbohydrates (Wang et al, 2013;Carvalho et al, 2014;Ribeiro et al, 2016) or lipids (Altaee et al, 2016;Riedel et al, 2015;Morais et al, 2014;Shahzad et al, 2017), the use of complex substrates containing high fractions of both nutrients is an approach scarcely investigated in PHA synthesis .…”